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The traditional electrospinning needles are easily blocked and the processing is not suitable for mass production. In order to address the problems, this study uses a rotary linear electrode for electrospinning for the production of polyvinyl alcohol (PVA)/chitosan(CS)/graphene(Gr) nanofibrous membranes. The membranes are observed for micro-structure and tested for thermal stability, surface resistivity, and hydrophilicity, thereby examining the influence of the content of chitosan. The test results show that the presence of chitosan improves the hydrophilcity as well as affects the morphology of PVA/CS/Gr nanofibrous membranes where the nanofiber diameter is smaller. Moreover, FTIR results suggest that chitosan and PVA interact to generate hydrogen bonds that stabilize the thermal properties of nanofibrous membranes. In particular, the maximum thermal decomposition temperature of PVA/CS/Gr nanofibrous membranes composed of PVA/CS ratio being 9:1 is 297.7 ℃. Finally, using chitosan also increases the electrical conductivity and decreases the surface resistivity. This fabricated technique provides the possibility of mass-production of PVA/CS/Gr nanofibrous membranes in the future. Keywords: Rotary linear electrospinning, Nanofibrous membrane, Chitosan, Graphene, Thermal stability, Conductivity

Inspired by pomelo peel, this study proposes bioinspired foam composites, which are prepared by one-step foaming and a combination of different fabric structures. The bioinspired composites are evaluated in terms of compression resistance, bursting strength and cushioning efficacy, thereby examining the influential mechanisms of fabric structures. The experimental results indicate that the bio-inspired composites have superior functions due to the reinforcement of a nylon fabric as well as high stiffness and energy absorption of polyurethane -based small-mesh-size spacer fabrics. The bioinspired foam composites have maximum compression resistance is 131 kPa with a corresponding strain of 60%, which is 245% greater than the control group. The deformation-absorption energy of bioinspired foam composites is 2.3 J, which is 78% greater than that of pomelo peel. The maximum bursting strength of bioinspired foam composites is 3370 N, which is two and twenty times that of the control group and pomelo peel, respectively. Compared to spacer fabrics at 0° lamination, spacer fabrics at 90° lamination has a positive influence on the bursting strength but a negative influence on compressive strength of bioinspired foam composites. Bioinspired foam composites have a peak contact force that is 45.1% lower than that of the control group, which suggests remarkable improvement in energy absorption. The resultant bioinspired composites are expected to be used as packaging and personal protective materials for commercial applications in the future.

Elastic knits are one textile that have a high extensibility, which helps to restrain the body and attain both effects in terms of health protection and body sculpture. These qualities make...

Nylon fabrics are used as the reinforcing upper layer. A warp-knitted spacer fabric that is saturated with flexible polyurethane foam is used as the lower layer. They are combined in order to form innovative impact energy absorbent composite sandwiches employing a two-step foam process. The quasi-static compressive strength, bursting strength, and dynamic shock cushioning characteristic of the composite sandwiches are evaluated, the latter of which is tested using a drop weight impact tester in order to simulate the impact resistance corresponding to complex environments. The experimental results suggest that a combination of warp-knitted spacer fabric increases the compressive strength and bursting strength of composite sandwiches by 107% and 60%, respectively. The shapes of impactors determine the contact force and dynamic impact time. The greater contact area results in the smaller contact force, indicating that the composite sandwiches have greater cushioning efficacy. Designed with a gradient combination, the flexible polyurethane foam strongly bonds the upper polyamide nonwoven fabric and the lower warp-knitted spacer fabric. The optimal compression resistance, a bursting strength of 1677 N, and a maximum energy absorption of 90% at a 15 J impact energy are presented. The innovative composite sandwiches have a promising perspective in packaging and individual impact protection in the future.

Protective clothing with electromagnetic shielding effectiveness (EMSE) is a functional textile, which shields electromagnetic waves to protect the human body from the far infrared rays. Traditional EMSE garments primarily use metallic plates for reflecting electromagnetic interference (EMI). However, they also have disadvantages of a heavy weight, easy corrosion, and high production cost. In this study, three different functional yarns are combined, during which the twist number of metallic wires is changed for a better shielding effect. A crochet machine is used to fabricate functional elastic knits with the metallic composite yarns as the warp- and weft-inlaid yarns. The test results show that double (D) functional elastic knits exhibit EMSE of above 20 dB when the EMI are between 1.0 and 3.0 GHz. In addition, the knit structure can improve breaking tensile strength by 170 % and increases bursting strength by 58 %, but undermines the tear strength by 10 %. Although changing twist number of metallic composite yarns does not affect water absorption rate along the weft direction, it helps increasing elastic recovery rate by 3.1 %, water absorption rate along the warp direction by 106 %, far-infrared emissivity by 2.3 %, water vapor transmission rate by 20 %, and air permeability by 6 %.

Polyethylene terephthalate (PET) nonwoven fabrics, carbon fabrics (CF), and flexible polyurethane (PU) foams are made into novel sandwich composites using one-step molding. The flame retradance and mechanical properties of the sandwich composites are evaluated, examining the influences of the content of flame retardant agent (20, 30, 40, and 50 wt%) and areal density of PET panels (200, 300, and 400 g/m2). The test results show that the PET/CF/PU sandwich composites are rated flame retardant as V0 and do not generate melts. The failure mode of PET/CF/PU sandwich composites converts from overall fracture to layered fracture as a result of increasing the flame retardant agent. The tensile strength at break of PET/CF/PU sandwich composites with corresponding PET panels is 650 N for 200 g/m, 928 N for 300 g/m, and 1744 N for 400 g/m2, which are 42.63 %, 60.48 %, and 77.85 % greater than those of the PET/PU sandwich composites. Moreover, the bursting strength of PET/CF/PU sandwich composites with corresponding PET panels is 3322 N for 200 g/m2, 3869 N for 300 g/m2, and 4978 N for 400 g/m2, which are 195%, 180%, and 143% greater than those of the PET/PU sandwich composites.

This study investigates the mechanical properties and damage behavior of flexible laminated composites. Needle punching is performed to combine woven Kevlar fabric and two nonwoven low-melting point polyester (LMPET) fabrics into a fabric interlayer. A sheet-extrusion machine is used to bond two thermoplastic polyurethane (TPU) sheets on each side of a fabric interlayer. The tensile strength, peel load, and static puncture resistance of the flexible laminated composites are evaluated, and the influences of needle-punching rates and depths are examined. Test results show that a high needle-punching rate or depth positively affects tensile strength by promoting fiber entanglement. The tensile strength of the 300-15 group reaches 24.70 MPa. Moreover, when the needle-punching depth does not exceed 11 mm, melted LMPET fibers help bond two-phase materials and thus increase the peel loads of the final composites. The 200-11 group has an optimal puncture resistance of 5.86 N. The combination of TPU sheets and woven Kevlar fabrics yields flexible laminated composites with good static puncture resistance. The results of this study can be applied to improve the performance of flexible laminated composites.

In modern age, prosperous business, industrial, social, and leisure activities improve and ensure the quality of lives considerably, but are inevitably accompanied with insecurity and dange...

Conversion of aqueous arsenite [As(III)] to less toxic arsenate [As(V)] is a critical step for the arsenic pollution remediation. In this study, Ag2O/TiO2 composites synthesized via the pH-induced precipitation method were employed into the photocatalytic oxidation of As(III) under visible light irradiation. X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy analysis verified the formation of Ag2O/TiO2 heterostructures. Compared to pure Ag2O and TiO2, the 30% Ag2O/TiO2 composite exhibited much higher photochemical reactivities for the oxidation of As(III) under visible light irradiation. Under the optimal conditions [pH = 4.0, the photocatalyst dosage being 0.3 g L−1 and initial As(III) concentration being 10 mg L−1], the oxidation and removal percent of As(III) was 60.7% and 83.0% after reaction for 120 min, respectively. Moreover, the formation of Ag(0) over the surface of Ag2O by photo-induced electrons contributed to the high stability of Ag2O/TiO2 composite. It was also found that photo-generated holes and superoxide radicals played the predominant roles in the As(III) oxidation. The improved photocatalytic activities were attributed to the formation of the hetero-junctions between Ag2O and TiO2, the strong visible light absorption, and the high separation efficiency of photo-generated electron-hole pairs resulted from the Schottky barriers at the Ag-Ag2O interface.

In this study, functional woven and knitted fabrics consist of stainless steel (SS) composite yarns. SS fibers (0.06 mm) and 500 D polyester (PET) filaments are used as the core with 70 D bamboo charcoal (BC) nylon fibers that are being used as the sheath in order to form the functional SS composite yarns. The test results show that the double-layered knitted fabrics have the optimal far infrared (FIR) emissivity of 0.85 ε, while the five-layered composite woven fabrics at 90° lamination angle have the optimal electromagnetic shielding efficacy between −50 dB and −60 dB. It is anticipated that the functional fabrics can be used in protective cloth and safety appliance.

Glass geotextile reinforcement and needle-punch bonding are applied to compensate for the low mechanical strength of a geotextile clay liner (GCL) and reduce damage under complicated service condit...

In this study, a new type of flexible sandwich composite with nonwoven facesheets and core reinforced by polyurethane (PU) grid sealing shear thickening fluid (STF) has been presented. With the specific design, the STF was sealed into PU grids as the core to provide shear thickening effect against impact. Rheological property of STF with different mass ratio and PU morphology after first and second foaming were evaluated and optimized for sandwich composite preparation. Both static compression and dynamic impact tests were carried out to obtain the impact dynamic response and investigate the effects of typical parameters including STF volume, core thickness and striker height on low-velocity impact behavior. The test results showed that the optimal concentration of STF was 20 wt.%, whose critical shear rate was 100s−1. The presence of STF had a positive influence on the static compression strength and dynamic impact strength. In particular, the 70% STF volume fraction contributed to the highest compression modulus. The compression modulus was 445 MPa and 466 MPa when the sample thickness was 2 cm and 3 cm, respectively. As for dynamic impact strength with corresponding STF volume fractions, it was 4535.31 mJ for 30%, 4599.72 mJ for 50%, and 4827.46 mJ for 70%, all of which were much higher than that (2348 mJ) of control group (without STF). Regardless of whether the STF volume being 30%, 50% and 70%, the impact displacement of composite was within 10 mm, showing better impact resistance than control group (13.16 mm). Besides, this composite with special PU grid sealing, STF structure demonstrated a certain strain rate effect. The higher the impact energy, the greater the energy absorption was. Specifically, impact energy absorption rate of composite with a thickness of 3 cm was as high as 52.3% under 350 mm impact height.

Water was the source of life, in order to solve the serious water pollution problem facing the world, researchers have proposed many solutions. Among them, photoelectric catalytic technology based on semiconductor materials was an ideal and sustainable solution. Herein, by combining successive ionic layer adsorption and reaction (SILAR) with sol-gel electrospinning two strategies, a novel S-scheme heterojunction based on flexible and hierarchical BiOI/TiO

Raw lacquer (RL) is a natural polymer compound with highly promising applications, however, its inflammable attribute restricts the industrial applications. In this study, melamine is used to formulate tri (1-melamine-2-propanol) phosphate (FR-1), after which it is synthesized with ammonium phosphate (FR-2) and diatomite to form a compound phosphorus-nitrogen intumescent flame retardant (IFR). Next, IFR is used as the filling agent that then cross-links with RL, and as such RL/IFR membranes are formed after the curing. The limiting oxygen index (LOI) measurement, the vertical combustion test (UL-94), the microshape calorimetric analysis (CCT), and the thermal gravimetric analysis (TGA) are conducted to examine the combustion resistance and thermal stability of the membranes. Fourier transform infrared spectroscopy (FT-IR) and electron scanning microscope (SEM) are performed to separately characterize the structure and compatibility, the mechanical properties of the membranes are also evaluated. The vertical combustion test results confirm that with 30 wt% of IFR, RL/IFR membranes acquire 12.3% higher LOI and a vertically combustion of V-0 level. The TGA indicates that RL/IFR membranes demonstrate a greater adhesion level, a higher rigidity, and better luster than pure RL membranes.

Composite materials prepared from polylactic acid have been used more and more widely in many fields. However, PLA has high brittleness, which largely restricts its application. Blending PLA with polycaprolactone (PCL) helps improve the disadvantages of pure PLA. In this study, different molecular weights of PCL were used and blended with PLA in different proportions to form a composite film by melt blending. The mechanical properties, thermal properties, and water wettability of Composite films are evaluated to examine the influences of the relative molecular weight of PCL and PCL/PLA ratio. When the relative molecular weight of PCL is 50,000, Composite films have high stress, strain, hydrophilicity, thermal properties, and UV-resisting property, but their thermal properties are not affected. At a specific relative molecular weight of PCL and PCL/PLA ratio of 30/70, the composite films reach their maximum stress and exhibit high strain, good hydrophilicity, and UV transmittance lower than 10%. Moreover, the PCL/PLA ratio has a marginal effect on the thermal properties of the composite films. This research has certain significance for promoting the application of PCL/PLA composite film in many fields.

Particulate matter 2.5 (PM2.5) has become a public hazard to people&rsquo, s lives and health. Traditional melt-blown membranes cannot filter dangerous particles due to their limited diameter, and ultra-fine electrospinning fibers are vulnerable to external forces. Therefore, creating highly efficient air filters by using an innovative technique and structure has become necessary. In this study, a combination of polypropylene (PP) melt-blown and polyvinyl alcohol (PVA)/zeolite imidazole frameworks-8 (ZIF-8) electrospinning technique is employed to construct a PP/PVA/ZIF-8 membrane with a hierarchical fibrous structure. The synergistic effect of hierarchical fibrous structure and ZIF-8 effectively captures PM2.5. The PP/PVA composite membrane loaded with 2.5% loading ZIF-8 has an average filtration efficacy reaching as high as 96.5% for PM2.5 and quality factor (Qf) of 0.099 Pa&minus, 1. The resultant membrane resists 33.34 N tensile strength and has a low pressure drop, excellent filtration efficiency, and mechanical strength. This work presents a facile preparation method that is suitable for mass production and the application of membranes to be used as air filters for highly efficient filtration of PM2.5.

Chitosan (CS) combined with hydroxyapatite (HA) was injected into a composite braid, and a hierarchical pore structure scaffold was obtained by freeze drying and cold atmospheric plasma (CAP) technology. The CS/HA/braid scaffold with hierarchical pore structure was analyzed and characterized by scanning electronic microscopy, Fourier transform infrared spectroscopy, true color confocal microscopy, improved liquid replacement method, and phosphate buffer solution immersion. The mechanical properties and degradation ability of the scaffold were evaluated through compression test and degradation test. Results showed that HA addition endowed the core of the scaffold with macroscopic pore sizes of 80-180 μm, and CAP treatment endowed the shell of the scaffold with microscopic pore sizes ≤10 μm. All scaffolds exhibited high porosity and swelling rates of ≥80 % and ≥300 %, respectively. The scaffold with a hierarchical pore structure had good mechanical properties and twice the degradation rate. In addition, the treated scaffold precipitated intact spherical HA crystals. Under the synergistic effect of HA and CAP treatment, scaffolds achieved 277.6 % cell viability compared with pure CS scaffold. Overall, this method was feasible for preparing bone scaffolds with hierarchical pore structure for potential bone tissue engineering.

This study reports a novel adsorbent structure and shows the satisfactory removal performance of Pb(II) and Ni(II). The fabric structure increases the strength of the hydrogel. The hydrogel plays a major role in the composite structure as a matrix, while the fabric bears the applied load and protects the structure from mechanical damage. The double-network composite hydrogel is reinforced by plasma grafted polylactic acid melt-blown non-woven fabric and polyethylene glycol dimaleate, and its compressive strength reaches 40.6 kPa at 60% strain. The interface substantially improves the compression strength by 42.9%. Through the adsorption isotherm model, the adsorption capacity of the hydrogel for Pb(II) and Ni(II) reaches 233.12 and 165.06 mg/g, respectively, and the removal rate of heavy metal ions in water at low concentrations exceeds 95%, showing the excellent removal rate of heavy metals. Even after the fifth cycle, the removal efficiency barely declines, indicating the feasibility of repeatedly use. Cost analysis reveals that the adsorbent is relatively low cost, solving the problems of difficult recovery, low strength, and easy damage of hydrogel adsorbents, and promoting the industrial application of hydrogels as adsorbents.

Three-dimensional braided composite has a unique spatial network structure that exhibits the characteristics of high delamination resistance, damage tolerance, and shear strength. Considering the characteristics of braided structures, two types of high-performance materials, namely, aramid and carbon fibers, were used as reinforcements to prepare braided composites with different hybrid structures. In this study, the longitudinal and transverse shear properties of 3D braided hybrid composites were tested to investigate the influences of hybrid and structural effects. The damage characteristics of 3D braided hybrid composites under short beam shear loading underwent comprehensive morphological analysis via optical microscopy, water-logging ultrasonic scanning, and X-ray micro-computed tomography methods. It is shown that the shear toughness of hybrid braided composite has been improved at certain degrees compared with the pure carbon fiber composite under both transverse and longitudinal directions. The hybrid braided composites with aramid fiber as axial yarn and carbon fiber as braiding yarn exhibited the best shear toughness under transverse shear loading. Meanwhile, the composites with carbon fiber as axial yarn and aramid fiber as braiding yarn demonstrated the best shear toughness in the longitudinal direction. Due to the different distribution of axial and braiding yarns, the transverse shear property of hybrid braided structure excels over the longitudinal shear property. The failure modes of the hybrid braided composite under the two loading directions are considerably different. Under transverse loading, the primary failure mode of the composites is yarn fracture. Under longitudinal loading, the primary failure modes are resin fracture and fiber slip. The extensive interfacial effects and the good deformation capability of the hybrid braided composites can effectively prevent the longitudinal development of internal cracks in the pattern, improving the shear properties of braided composites.

Terrorist attacks occur constantly, which subsequently arouses awareness of self-protection. In order to alleviate the harm caused by sharp objects of knives and daggers, a design of flexible stab-resistant materials that are impregnated with the shear thickening fluid (STF)/multi-walled carbon nanotubes (MWCNTs) system and different texture of fabrics is presented. STF/MWCNTs are composed of polyethylene glycol (PEG 200) as the dispersion medium and silica (SiO2) of 12 nm and 75 nm as disperse phase as well as MWCNTs as supplementary reinforcement, in expectation to provide the aramid fabrics with high strengths, low critical shear rate, and a short thickening response time. The textures of aramid fabrics—plain (P), twill (T), satin (S), or basket (B) weave—are saturated in the STF/MWCNTs system. The synergetic influences of silica size and texture on tensile strength, quasi-static knife, and spike stab resistances of the STF/MWCNTs-impregnated aramid fabrics are examined. Results show that the plain aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2(SM12) exhibit the maximum tensile strength and quasi-static knife stab resistance, 14.7 MPa and 8.9 MPa, respectively, which is 1.15 and 1.43 times higher than pure aramid fabrics. Moreover, the basket-weave aramid fabric immersed in the STF/MWCNTs system containing 12 nm SiO2have the maximum quasi-static spike stab resistance of 17.12 MPa compared to other textures of fabrics, which is 1.05 times higher than those immersed in the 75 nm SiO2STF/MWCNTs (SM75) system and 1.33 times higher than that of pure basket aramid fabrics.

This study combines and twists 75D polyester (PET) multi-filaments and polylactic acid (PLA) multi-filaments with twist coefficients of 2, 3, 4, 5, and 6 to form 150D PET/PLA plied yarns. The 0.08-mm-diameter stainless steel (SS) fibers are made into SS braids with a 60-tooth braid gear and a take-up gear with 60, 70, 80, 90, or 100 teeth. PET/PLA plied yarn and SS braids are then combined and electrochemically treated with an electric current of 100, 200, 300, 400, or 500 mA at 60 °C for 24 hours, forming the PET/PLA/SS composite bone scaffolds. PET/PLA/SS composite bone scaffolds are observed by scanning electron microscope (SEM) and energy dispersive spectroscope (EDS), and tested for weight increase rate and biocompatibility. The experiment results show that the optimal twist coefficient for PET/PLA plied yarn is 4 and the optimal tooth number on the take-up gear for SS braids is 80. SEM observation result shows that hydroxyapatite (HA) deposits on the surface of PET/PLA/SS composite bone scaffolds and attaches to the PET/PLA plied yarns. Finally, regardless of electric currents, all PET/PLA/SS composite bone scaffolds possess good biocompatibility.

In order to deeply explore the fiber characteristics influencing on stab resistance of shear thickening fluid (STF)- impregnated fabrics, two different weaving fabrics, ultra-high molecular weight polyethylene (UHMWPE) fabric and Kevlar fabrics are saturate the various concentrations and particle size of STFs. Result shows that, SiO2/PEG-200 blends demonstrate quick shear-thickening property, and the critical shear rate lowers to 1.2-45 s-1 with higher concentration of 75 nm SiO2. STF concentration and particle size significantly affect spike puncture resistance property, but the knife stab resistance mainly depends on fiber characteristics. Comparatively, STF-UHMWPE composite fabrics exhibit better knife stab resistance but weaker spike puncture resistance than STF-Kevlar fabrics. This study can provide an optimization for structure design of stab resistance armors in the future.

Protective textiles require massive consumption of fibers and fabrics, which is responsible for diverse highstrength fabric waste. Wrongly arranged disposal of textile waste is equivalent to the waste valuable resource while causing environmental pollutions. Aramid selvages are worthwhile recycling and used in this study. They are scattered into Aramid staple fibers and mixed with low melting point polyester (LMPET) fibers to form the Aramid matrices employing the nonwoven process. The matrices are added to different combinations to form Aramid composite matrices and hybrid-fiberreinforced composite boards. The process of shearing, crowding, and friction helps improve the mechanical properties of the composite boards according to the evaluations of conducted tests. With the premise of minimum damage to the fibers, this study uses recycled Aramid waste to produce composite boards that have features of high performance and low production cost. As a test result, the hybrid-fiber-reinforced composite boards with 90 wt% of recycled Aramid fibers have the optimal mechanical property and static puncture resistance.

To characterize the interfacial microstructure and interaction at a nanoscale has a significant meaning for the interface improvement of the nanocomposites. In this study, the interfacial microstructure and features of aligned multiwalled carbon nanotube (MWNT) and conjugated polymer polyimide (PI) with three molecular structures were investigated using small-angle X-ray scattering (SAXS), wide-angle x-ray diffraction (WAXD), and fluorescence emission spectroscopy. It was found that aligned MWNT/PI nanocomposites had a nonideal two-phase system with the interfaces belonging to long period stacking ordered structure. Attributed to the &pi, &ndash, &pi, stacking effect, MWNT/BTDA-MPD presented the most regular arrangement verified by fractal dimension. By adopting a one-dimension correlation function, each phase dimension in aligned MWNT/PI nanocomposites was calculated and verified by high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The &pi, stacking was demonstrated to be an important interaction between MWNT and PI via WAXD and fluorescence emission spectroscopy, and it was influenced by the linkage bond between benzene rings in PIs. This work is of significance to reveal the interfacial features between conjugated polymer and carbon nanotubes (CNTs), which is favorable for the interface design of CNT-based high performance nanocomposites.

This study proposes composite knits that have multiple functionalities to fit a diversity of applications. Stainless steel/rayon (S/R) wrapped yarns are used as the sheath and bamboo (B) charcoal polyester yarns are used as the core to form SRB wrapped yarns. The SRB wrapped yarns are made at number of twists of 2, 3, 4, 5, or 6 turns/cm. Moreover, the composite knits are made of SRB wrapped yarns as the face yarns and Tetoron® yarns as the ground yarns using a computer jacquard hose machine. The surface resistance, electromagnetic shielding effectiveness (EMSE), elastic recovery, anion release, and softness of the composite knits are measured, investigating the influence of the number of twists as well as the functionalities of the composite knits. When the number of twists is 4 turns/cm, the composite knits have an optimal elastic recovery of above 71.8%, optimal anion release of 408 counts/cm3, a greater softness along the wale direction, and optimal EMSE of 20 dB at frequencies of 2.18E+08 Hz.

Compared with a rigid polyurethane foam, a flexible polyurethane foam (FPUF) has more diversified applications including filtration, sound absorption, vibration-proofing, decoration, packaging, and heat insulation. However, its most potential hazard is flammability. Therefore, in this study, we focused on improving its flame retardation and then tested its sound absorption with the addition of nitrogen/phosphorus synergistic flame retardants. The influence of phosphorus-based flame retardants (TCPP, TDCP, and V6) and a nitrogen/phosphorus synergistic flame retardant (melamine-TDCP) on its microstructure, compressive stress, sound absorption, thermal stability, and flame retardation was systematically explored. The presence of phosphorus flame retardants improved the sound absorption but considerably decreased the mechanical properties. The melamine-TDCP compound flame retardant delivered smaller cells and thus increased the compression property of the resulting foam. Moreover, with a higher content of melamine, the initial mass-loss temperature also increased. In particular, on using TDCP and 5 wt% of melamine as flame retardants, the compressive stress increased by 3.4 times, the average sound absorption coefficient was 0.45, and LOI reached 25.5, which met the requirements of industrial flame retardant/sound absorbent materials. This resultant flame retardant/sound absorbent flexible polyurethane foam can serve as a mattress and furniture pad material, vehicle seat cushion material, and liner for laminated composites in the future.

The reaction of the lanthanide(III) β-diketonate salt (Dy(beac)3·2H2O) with a bidentate chelating ligand 5-(2-hydroxy-5-methylbenzylidene)-8-hydroxylquinoline (HL) afforded the tetranuclear Dy(III) cluster, [Dy4(μ3-OH)2L6(beac)4]·10CH3CN (1). The elemental analysis (EA), powder X-ray diffraction (PXRD), single-crystal X-ray diffraction and magnetic properties of 1 have been characterized. The X-ray structural analysis reveals that cluster 1 contains one Dy4 center with a rhombus-shaped arrangement, and each Dy(III) ion of 1 is located in a distorted square antiprism geometrical configuration. Magnetic properties study indicate that 1 shows single-molecule magnet behavior with larger energy barrier (ΔE/kB) of 78.3 K and τ0 = 4.4 × 10−7 s.

This study aims to construct tissue engineering stents by using the long fiber-reinforced thermoplastic (LFT) technique to develop artery stents. The experimental method combines fibers, the LFT technique, and electrospinning technique. First, the biodegradable polyvinyl alcohol yarns are twisted and coated in polycaprolactone/polyethylene glycol blends through the LFT technique. Next, the weft-knitting and heat treatment are used to establish the stent structure, after which poly(ethylene oxide) (PEO) is electrospun to coat the stents. The morphology, mechanical, and biological properties of tissue engineering stents are evaluated. The test results indicated that the use of the LFT technique retains the softness of filaments, which facilitates the subsequent weft-knitting process. The coating of blends and electrospinning of PEO have a positive influence on the tissue engineering stents, as demonstrated by the tensile strength of 59.93 N and compressive strength of 6.10 N. Moreover, the in vitro degradation of stents exhibits a stabilized process. The water contact angle is 20.33°, and the cell survival rate in 24 h is over 80%. The proposed tissue engineering stents are good candidates for artery stent structure.

This study aims to develop nanofibrous membranes where Eucalyptus globules oil (EGO) is wrapped in polyvinyl alcohol (PVA). The EGO-based nanofibrous membranes are then evaluated for the protection against Forcipomyia taiwana (F. taiwana). In the first stage, the PVA solutions are formulated with different concentrations and are measured for viscosity and electrical conductivity. In the next stage, PVA solution and EGO are blended at different ratios and electrospun into PVA/EGO nanofibrous membranes (i.e., EGO-based repellent). In this study, a PVA concentration of 14 wt% has a positive influence on fiber formation. Furthermore, the finest nanofibers of 291 nm are presented when the voltage is 15 kV. The repellent efficacy can reach 80% in a 60-min release when the repellent is composed of a PVA/oil ratio of 90/10. To sum up, the nanofibrous membranes of essential oil exhibit good repellent efficacy against F. taiwana and significant slow-release effect, instead of adversely affecting the cell viability.

In this study, titanium dioxide (TiO2), a mineral with a potential and supercapacitor, is used as the reinforcing material to improve the filtration efficacy of electret melt-blown fabrics. Next, the electret melt-blown fabrics are evaluated in terms of surface voltage and filtration efficiency, thereby examining the influences of the TiO2 ratio and electric field intensity. The test results indicate that the filtration efficiency is proportional to the ratio of TiO2 and electric field intensity. In particular, with a TiO2 ratio of 3 wt% and an electric field intensity of 2.5 kV/cm, the electret melt-blown fabrics demonstrate a maximal filtration efficiency of 96.32%, a lowest pressure drop of 40 Pa, and an optimal quality factor of 0.083 Pa-1.

Superhydrophobic aerogels are attractive candidates in controlling oil spills. The major challenges for existing aerogels are the construction of mechanical endurance as well as accessible of building materials. Herein, a newfangled biomass superhydrophobic aerogel (M-PCF/CS) with both superior compressibility and oil caption speed is fabricated by assembling poplar catkin fiber (PCF) hollowed-out shell of 330 nm and chitosan (CS) into tubular-lamellar interweaved neurons-like structure. The resultant aerogels (porosity ~ 96.12%), with flexuous PCF as the elastic buffer and second-pore capillaries, exhibit large longitudinal and transverse compressibility, endurable fatigue tolerance, fast oil sorption rate with a capacity of 28.8-78.1 g/g at 5-25 s. In parallel, the aerogels are tolerant of NaCl, UV radiation, and organic solvents without superhydrophobic variation and a case of oil spill remediation via pump-supported experiment shows that the aerogels facilely achieve continuous oil recycling from seawater by 23052-43956 L·m